Here's an unusual one that I acquired recently, a bowed or streich zither. It has four strings tuned in fifths e'a'DG like a violin and played with a bow. In fact many of these were made in the form of violins or from violins; Schwarzer advertised a large stock of violins which he would make into a streich zither on request. This one is made in the heart-shaped form of the traditional Bavarian folk instrument. During the mid-19th century, the bowed-zither was the rage. Duke Maximilian of Bavaria was apparently quite the zither enthusiast, and wished it to be Bavaria's national instrument. This one comes in a beautiful case with a painting of a lake and sailboats, which my wife tells me is probably Lake Constance where her grandmother lived.( I really bought the instrument for the case.)